Vlk,
OK, immediately after experiencing the problem, I disabled avast!'s self-defense, went to Task Manager and right clicked the AshWebSV.exe process and clicked on Create Dump File but, the computer seemed to hang while on "wait while writing file..." I waited about 8 minutes for it noticing that the hard drive was not moving at all, canceled and tried again, but this time Vista came back with an access denied message. I stopped On-access protection and it was still in there so I tried again, and again got access denied. I looked around the root directory and the Alwil directories, my home directory, with hidden files visible and didn't see anything that looked like a dump file. The procedure never got to the point of asking me to name the file. Perhaps I should have waited longer. What would the file have been named in case it was created (where might it be, I may have missed it)? Do you have any idea what else I might do?
This time I was able to get Firefox to reconnect by disabling avast on-access protection. I also noticed that some links on open tabs were able to connect before disabling (i.e. Google and others) but links on others which were open (avast! forum) I was not able to connect. I had not opened those links that I was able to open prior to the problem occuring. Links from unopened bookmarks were not able to connect at all, home page did not connect. All this was fixed with disabling on-access protection.
This is really starting to wear me down. :-)